Light update to one of my favorites. Before, we could do this:

iex> import PredicateSigil
...> Enum.filter([1,2,3,4], ~p(3))
[3]
# ~p(3) === fn 3 -> true; _ -> false end

But sometimes the awesome Enum and Stream APIs don’t have the negated version of what you want - so now you can also:

iex> Enum.take_while([1,2,3,4], ~p(!3))
[1,2]
# ~p(!3) === fn 3 -> false; _ -> true end